Process for finishing surfaces

ABSTRACT

A novel wiping-type color composition is provided containing (A) a volatile organic liquid, (B) a dispersed polymer (e.g. an acrylic polymer) in the form of tiny solid coalescible particles which are insoluble in (A) at normal storage conditions and will not coalesce when applied at 25*C. and (C) a dispersed pigment which is present in an amount such that the (B):(C) weight-ratio is about 1:99 to 40:60. The process of applying this organosol is also claimed.

United States Patent 1 Craven PROCESS FOR FINISHING SURFACES [75]lnventor: James Milton Craven, Wilmington,

Del.

[73] Assignee: E. I. du Pont de Nemours and Company, Wilmington, Del.

[22] Filed: June 29, 1971 [21] Appl. No.: 158,093

Related US. Application Data [63] Continuation-impart of Ser. No.834,505, June 18,

1969, abandoned.

[52] US. Cl 117/10, 117/63, 117/72, 117/132 C, 117/148 [51] Int. Cl B44d1/02, B44d H44 [58] Field of Search 117/37, 63, 8, 161 UN, 117/161 UT,161 UC, 132 C, 148, 10

[56] References Cited UNITED STATES PATENTS 1,712,600 5/1929 Westphal117/63 1,994,269 3/1935 Bonniksen 117/63 2,431,078 11/1947 Powell et a1.117/37 X 2,565,602 8/1951 Fisher et al. 117/37 X 2,568,765 9/1951 Roonet al. 117/37 X [4 Dec. 4, 1973 Primary ExaminerWilliam D. MartinAssistant ExaminerDennis C. Konopacki Attorney-Robert W. Black [57]ABSTRACT A novel wiping type color composition is provided containing(A) a volatile organic liquid, (B) a dispersed polymer (e.g. an acrylicpolymer) in the form of tiny solid coalescible particles which areinsoluble in (A) at normal storage conditions and will not coalesce whenapplied at 25C. and (C) a dispersed pigment which is present in anamount such that the (B):(C) weight-ratio is about 1:99 to 40:60. Thepro cess of applying this organosol is also claimed.

8 Claims, No Drawings r l PROCESS FOR FINISHING SURFACES Thisapplication is a continuation-in-part of US. Ser.

No. 834,505, filed June 18, 1969, now abandoned.

The present invention provides an organosol composition suitable for useas a wiping stain, filler, or glaze for wood furniture; The organosolhas a film-forming polymer of at least 50 percent acrylic monomer unitsdispersed with a pigment, as hereinafter described which polymer doesnot coalesce under typical conditions of application, i.e., ambientatmospheric conditions, but which polymer will coalesce on exposure tocoalescing means. The powder-like nature of uncoalesced polymer aids inthe wiping or glaze application. The polymeric component will coalescein a subsequent coalescing step. i

The present invention comprises a dispersion comprising a continuousorganic liquid phase and a dispersed phase comprising A. particles of alinear polymer which polymer has a Tg between about C. and 70C., isamorphous and has at least 50 percent by weight of acrylic monomerunits, said dispersed polymer phase being substantially insoluble insaid liquid phase at temperatures up to about 38C., and

B. particles of a pigment, the weight ratio of A:B being about 1.:99 to40:60 said dispersed polymer being present in an amount of less thatpercent by weight, said dispersion forming a noncoalescing layer whenapplied and dried by evaporation of volatile components in the liquidphase at temperatures up to about 38C. Preferably the Tg of the polymeris between about 25C. and 70C. and most preferably wherein the polymerhas a Tg of between about 40C. and 70C.

The polymer present in the disperse phase is desirably at least onemember of the group consisting of poly(alkyl acrylates), poly(alkylmethacrylates), and interpolymers of about 50-999 percent by weight ofunits of an alkyl acrylate or an alkyl methacrylate and about 0. 1-50percent by weight of units of another ethylenically unsaturated compoundselected from the group consisting of --poly(vinyl acetate),polystyrene,

poly(vinyl-choride), poly('vinylidene chloride).

The weight ratio of A:B is in one embodiment between about 5295 and35:65. The composition may contain a dispersion stabilizer adapted torender the composition resistant to agglomeration and settling. Theparticles of the polymeric component have an average diameter in therange of about 0.01 to 25 microns. The particles preferably have anaverage diameter of about 0.05-l.0 micron.

This invention also includes a process which comprises applying to thesurface of a substrate the above dispersion and forming therefrom alayer of the dispersed phase having substantially no coalescence, wipingsaid surface with wiping'means to attain the desired appearance of thewiped layer on the surface and subjecting the layer to coalescing meansto form a substantially coalesced layer. Typically the coalescing meanscomprises contacting the layer with a solvent and subsequentlyevaporating the solvent.

The disperse phase is usually made of a polymer havof coalescence bypractical commonly used means (in application) and mar resistance underprolonged heavy load (of a surface in use). Raising Tg tends to resultin increased difficulty in coalescence. Lower Tg tends to decreaseresistance to flow under heavy load. The Tg range of the polymers in thedispersion of the claimed invention, results in satisfactory resistanceto flow of a surface in a finished article. Preferred ranges of Tgprovide even better use properties of the polymer in the finishedarticle.

Similarly, the amorphous nature of the polymer helps provide forcoalescence. This property together with solubility of the polymer incommon solvents tends to provide for coalescence by means not harmful tothe substrate to which this finish is applied.

Percent coalescence of a layer is measured by the abrasion resistance ofa layer compared to the abrasion resistance of a completely coalescedlayer of the same material determined as described hereinafter.

The dispersion of the present invention forms a substantiallyuncoalesced layer on evaporation of the volatile components of theliquid phase at temperatures up to about 38C. This is necessary in awiping composition to provide freedom to wipe a substrate withouttackiness. On the scale of percent coalescence a substantial absence ofcoalescence is a value of approaching zero.

Because conditions of the industry are such that work is accomplished atambient conditions the dispersion of the invention must form asubstantially uncoalesced layer at temperatures up to about 38C.(ambient environment).

Elevated temperatures are not considered satisfactory for wood for longexposures and therefore coalescence of polymer coatings for wood, onwood are best carried out by a solvent treatment" at room temperature orslightly elevated temperature. Polymers such as polyvinyl chloride whichrequire for purposes of this invention excessive heat to coalesce arenot considered suitable. 1 Y

DEGREE or COALESCENICE Degree-of coalescence is measured by the abrasionresistance'of a given laye'r of'polymer (film) in cycles/- mil (asdescribed hereinafter) as compared to the abrasion resistance of acompletely coalesced film. Degree of coalescence can be'determined asfollows:

Steel panels (4" X 4" with a 1/4" hole punched in ing a Tg of at least10C.; and in some applications a polymer having a Tg of at least 40C. ispreferred. ,Tg

refers to the "glass transition temperature.

The polymers of the claimed range have a Tg between such limits as toeffect a balance between ease center) are sprayed with a red, steelprimer and dried. The thickness of the primer on each panel is thenmeasured with an Elcometer (Elcometer lnstruments Ltd.,

-Droylsden, Manchester, England. Available from Gardner Laboratory,lnc., Bethesda, Md.). The primed panels are then sprayed with a solutionof the polymer to be tested and the organosol of the polymer to betested and dried at the desired temperature. The total thickness ofprimer and experimental material is then measured with the Elcometer andthe previously determined primer thickness subtracted to give thethickness of the experimental film.

The panels are then abraded on a Taber Abraser using 8-33 sandpaperstrips adhered to the outside of the two rubber wheels. Fresh sandpaperis used for each sample. Using a 250 g. load, the panels are abradeduntil one half of the abraded area of the experimental film iscompletely abraded away exposing the red primer underneath. The numberof cycles required to do this is divided by the thickness of theexperimen-. tal film to give the abrasion resistance in cycles/mil.Uncoalesced material should have no abrasion resistanceand should exposethe primer in about 1 cycle.

m'ary, secondary or tertiary alcohol, such as methanol, ethanol,isopropanol, butanol, amyl alcohol, methyl isobutyl carbinol,cyclohexanol, t-butyl alcohol, 2- ethylhexanol; C -C aliphatic oralicyclic ketone, such as acetone, diisobutyl ketone, methyl eth y lketone, ethyl amyl ketone, methyl isopropyl ketone, isophorone, methylisobutyl ketone, methyl isobutyl ketone, diethyl ketone, mesityl oxide,cyclo-hexanone, diacetone alcohol; esters of C,C aliphatic acid with aC,C aliphatic alcohol, such as ethyl acetate, isopropyl acetate, methylacetate, n-butyl acetate, sec-butyl acetate, isobutyl acetate, n-propylacetate,- amyl acetate, butyl lactate ethyl lactate, isobutylisobutyrate, cx-methyl isoamyl acetate; C2Cm The color composition ispreferably formulated so that it has good storage stability; forexample, a dispersion stabilizer is preferably present in an amountsufficient to render the composition as initially prepared resistant toundue settling and agglomeration of the nonvolatile components. In sucha composition, any solid components that settle out during storage ofthe composition, e.g., for about 3 months at about 22C., can usually beredispersed by a brief period of agitation.

10 One very useful stabilizer is illustrated in Example 1 below, inFormulas A and B. The graft copolymers described by Armour et al in theclaims of Swiss Pat. No.

464,528, granted Oct. 31, 1968, illustrate another useful type ofdispersion stabilizer.

substantially insoluble, at least under the conditions to which thecomposition will be exposed during storage, application to thesubstrate, and wiping of the colorcoat. The liquid is volatile in thesense that it can be evaporated under conditions which are not harmfulto polyether, such as mesityl oxide, butoxyethyl alcohol, 5 anycomponent ofthe coated substrate.

butoxyethyl acetate, monobutyl ether of diethylene glycol, monoethylether of diethylene glycol, ethoxyethylalcohol, ethoxyethyl acetate,monoethyl etheri of triethylene glycol, methoxyethanol, monomethyl etherof diethylene glycol.

To test for solubility, mix 0.03 g. of polymer powder in 1 ml solvent ina test tube and insert a stopper. Gentle shaking should be sufficient todissolve at least 95 percent of the polymer in less than 24 hours. Ifall the polymer dissolves to give a clear or hazy solution it isconsidered soluble. If a trace of insoluble powder remains undissolved,the polymer is still considered soluble. If the polymer remainsvisiblewhether swollen, broken up, emulsified or unaffected it isconsidered insoluble even though some may have.

dissolved.

lfa small portion, e.g., up to about 5 percent, of the polymer goes intosolution this may or may not harm the utility of the composition for aparticular application. Thus, if the portion dissolved is a lowmolecular weight fraction of the polymer, the composition might stillhave satisfactory spraying and wiping characteristics for some uses inspite of a slight increase in viscosity or tackiness. Generally however,the compositions which have the most beneficial utility and the bestapplication and wiping characteristics, are those in which none, orpractically none, of the polymer particles are dissolved or coalescedprior to completion of the wiping operation.

Some of the most useful embodiments of the composition employ analiphatic hydrocarbon as the liquid phase, for example naphtha, kerosenehexane, mineral spirits and the like, and blends thereof. Also usefulare mixtures of such liquids with up to about 25 percent, based on thetotal weight of the liquid phase of other kinds of volatile organicliquids, for example, aromatic hydrocarbons, ketones, esters, ethers,alkanols and the like and blends thereof. The liquid phase can consistof a mixture of a nonsolvent for the polymer component and a solvent forthe polymer as long as the solvent is not added in an amount which willresult in any harmful solvent action on the polymer particles, i.e.,result in coalescence of the applied layer. When using such a mixture,if there is undue coalescence of the polymer particles or an undueincrease in tackiness or viscosity of the color coat before the wipingoperation is completed, this indicates that the polymer is notsufficiently insoluble in the liquid phase. Among the correctivemeasures which can be taken to render such a composition useful arethese: (I) add more non-solvent; (2) use a less volatile non-solvent sothe solvent will evaporate first; (3) use a more volatile solvent; (4)use the colorcoat composition at a lower temperature and/or (5) 5 changethe polymer to the extent needed to render it more insoluble.

A coalescing solvent can be present in the composition. For example, asolvent/non-solvent mixture can be used as the liquid phase wherein atleast some of the solvent remains in the color coat after the wipingoperation has been completed and the non-solvent has been evaporated.The remaining solvent provides a means of coalescing the wipedcolor-coat; or the liquid phase can be a solvent for the polymer at anelevated temperature. Care is taken in the selection of the liquid phaseand the coalescing conditions so as to avoid any harmful reaction, e.g.,undue solvent attack on the substrate or any coating beneath the colorcoat. It is emphasized however that some of the most useful color coatcompositions of this invention are those in which the liquid phase iscompletely (or almost completely) free of any liquid which will serve asa coalesing solvent at temperatures in the range of about 40 95C, andhigher. n

In the interest of obtaining a color coat having the most practicalstorage and shipping characteristics, usually only part of the liquidphase matter is added to the original mixture withpolymer and pigment;then the rest of the liquid is added shortly before applying thecomposition to the substrate. Two important factors, of course, inselecting the amount and type of liquid to add at either stage are: thedesired color coat viscosity, and the desired color coat drying rate.One skilled in the art, after reading the present disclosure, will beable to select the type and amount of liquid phase that gives the bestresults in any particular application. 1

It is usually preferred that the composition has a polymeric content'ofabout 5-l5 percent by weight. In coating further dilution may bedesirable.

The pigment of the color-coat composition can be any pigment whichprovides the desired color characteristics in the dried, coalesced colorcoat, and which is not harmful to the formation of the coating or theproperties of the final product. This incLudes nearly all of thepigments known to be useful in coating compositions. Among the preferredpigments, especially when the substrate is wood,are burnt umber, rawumber, VanDyke Brown, burnt sienna, raw sienna, mineral block, litholred, titanium dioxide and the like. Other useful pigments areillustrated as follows: ferrite yellow-orange, zinc oxide, zinc sulfide,lead titanate, antimony oxide, zirconium oxide, white lead, basic leadsilicate, lithopone carbon black, other iron oxides of various colors,lead chromate and molybdate orange; also the pigments sometimes referredto as pigment extenders, for example, calcium carbonate, talc, barytes,diatomaceous earth, asbestine, china clay, silica and fine mica; alsovarious known nitroso-, nitro-, azoand pyrazolone pigments as well asbasicdye-, auxanthine dye-, anthraquinone-, phthalocyanine-, and vatcolor P gmen The composition can contain a small amount of a polymerchemically different from the dispersed polymeric phase or some otherfilm-former, in solution in the liquid phase as long as it does notprevent obtaining the desired coating, wiping, and coalescingproperties, as well as coating adhesion and durability and otherproperties of the finished product. The same applies to other additiveswhich can be dissolved or dispersed in the composition. For example thecomposition can contain one or more of the following: a dissolvedpolymer known to be useful has a stabilizer in polymer dispersions toprevent or retard agglomeration and settling of the particles; a dryingoil; an oil-modified alkyd or other synthetic resin; a plasticizer,e.g., a nonvolatile liquid, for the polymeric disperse phase or anyother polymer present, flatting agents; dyes; fungicides; Pd.. F 8,anqsgs a a e ts? the likein carrying out the process of this invention,at least one layer of the color composition described above is appliedto at least one surface of a substrate by any suitable coating method,for example by spraying, brushing, spreading, dipping, rolling orflow-coating. Then the coated surface is wiped with any suitable wipingmeans, for example an absorbent cloth, a piece of burlap, sponge,chamois, brush, roller or the like, until the wiped surface has thedesired appearance and the color coat remaining on the surface ispresent in the desired amount and location. lnsome applications the bestresults are obtainedwhen at least some of the liquid phase is allowed toevaporate before the surface is wiped. The term wiping is, used forthsake of convenience; it includes the concept of brushing the surface toobtain the desired color coat appearance.

After the wiping operation, any remaining liquid phase matter isevaporated and the color coat is subjected to the action of heat,solvent or other means capable of causing the particles to coalesce; asolidified coalesced Colo! F9515, Pbifllflil: W-

At least part of the liquid phase matter can be evaporated during orafter the coalescing of the polymeric disperse phase in some embodimentsof the invention. In other embodiments, all or practically all of theliquid phase is evaporated before causing the polymer to coalesce. Toillustrate: the original composition can be free of any liquid which isa solvent for the polymer at C.; all of the liquid phase matterremaining after wiping can be evaporated at 80C.; then the dried colorcoat can be heated at C. until the polymeric component has coalesced. Ina modification of the embodiment just illustrated, the composition cancontain a non-volatile liquid plasticizer for the polymer which willcause the polymer to coalesce at 95C., or at any other practicalcoalescing temperature one might select. This is one preferred means ofcoalescing the polymeric component by causing a solvent for theparticles to coalesce them, the solvent in this case being a nonvolatileliquid which remains in the color coat.

Another illustration of this concept, and a particularly preferredembodiment of the invention, comprises bringing a volatile solventfor-the polymeric component in contact with the wiped and dried colorcoat by applying thereto a coat of a substantially clearvcoatingcomposition containing a film-former dissolved in or dispersed in avolatile organic liquid containing said solvent. For example, asillustrated with the sealer coat used in Example 4 below, the clearcoating composition can contain the film-former in the form of fineparticles dispersed in a volatile organic liquid (containing saidsolvent) in which the film-former is substantially insoluble underconditions to which the composition will be subjected before it isapplied to the color coat. Or the clear coating composition can be asolution in a volatile organic liquid (containing said solvent) of atleast one film-former such as a drying oil, a synthetic resin or anatural resin. A film-former is selected which will have suitableadhesion to the color coat. After the volatile solvent has caused thepolymer to coalesce at the coalescing temperature selected, the solventis evaporated. The resulting product has a dried protective clear coat,e.g., top coat, in superposed adherence with the coalesced color coat.

One preferred product of the invention is an article comprising asubstrate which originally has relatively large pores e.g., as used inExample 4, and having a surface coated with a composite solidifiedfinish containing at least one wiped and dried coalesced coat of thenovel color composition, and at least one clear coat (through which onecan see the color coat) of a clear film-forming composition; forexample, a finish resulting from applying in sequence (a) at least onesurface preparation coat of a film-forming composition such as awashcoat, barrier coat, or both; (b) a wiped filler coat of the novelcolor composition; (c) a sealer coat of the clear composition; and (d) atopcoat of the clear composition. An acrylic polymer as described aboveis especially useful as the film-former in coats b, c, and cl as well asin coat (a).

Another preferred product has a finish as described in the previousparagraph except there is a wiped glaze coat of the color composition ininterposed adherence with coats c and d; again the acrylic polymer isvery useful as the filmfvrmer n ash of thesaats Other preferred productshave characteristics as described in the previous two paragraphs exceptthe substrate is one originally having relatively small pores, e.g.,articles made of maple wood; and in preparing the composite finish, awiping stain coat of the novel color composition is applied to thesuitably prepared substrate (instead of the filler coat) and wiped,dried and coalesced in accordance with the procedure described in thepresent disclosure, then the sealer coat and topcoat are applied. Also,as described above, it is often desirable to apply a glaze coat so as tobe in interposed adherence with the sealer coat and topcoat.

Although the most beneficial utility of the present invention willusually be realized when the substrate is made of wood, useful,attractive, and durable articles can also be made by applying the colorcoat to various other substrates; for example metal, leather, paper,fabrics, polymer coated fabrics and papers, molded plastic articles, andplastic sheet materials. Any of these substrates can have a smooth flatsurface, and the wiping operation can consist largely of removing acertain amount of the color coat in certain areas of the coated surface.However, the greatest advantages of the invention will usually resultfrom using a substrate whose surface is not entirely smooth, flat ornon-porous. Examples of especially useful substrates are: wood having avery noticeable grain pattern or visible pores, and various kinds ofsheet materials and molded articles whose surface has an attractivepattern of recesses or raised areas.

Porous and non-porous plastic articles can receive the same novel finishdescribed herein as wood articles. Items to be finished are oftencomposite articles containing both wood and plastic components, and insome cases other materials as well. The composite articles can bebeneficially finished according to the present invention. Components ofcertain kinds of plastics and other materials which are not sufficientlyresistant to the dispersions or solutions of the finishing compositionscan be supplied in a pre-treated condition, as is well known in the art.For example, a barrier coat can be formed on plastic articles by coatingthem with a solution or dispersion in a harmless volatile liquid of afilm-former resistant to attack by the organic liquids present in thefinishing compositions.

By using the finishing process and color-coat composition of the presentinvention, one can readily obtain products having a decorative andprotective finish which is'very adherent and durable. A finish can beobtained which is particularly resistant to damage by dragging suchobjects as dishes, suitcases and furniture across the coated surface andby dropping objects on the coated surface. Thus, the finish hasoutstanding utility when applied to furniture, floors,'wall panels andthe like which are made of wood; it is also useful when applied tovarious other substrates. Excellent appearance is readily obtainable incombination with the beneficial mar resistance. The mar resistance ofthe finish can be demonstrated by the commonly used coin mar test"wherein the edge of a coin is dragged across the coated surface and anyshearing, chipping or flaking of the coating is obseryed.

Furthermore, in contrast with certain widely-used color-coat processeswhich require a lengthy drying operation between wiping and topcoating,e.g., those using a drying-oil type film-former, the present processenables one to use a very brief drying cycle and still obtain excellentwiping characteristics, topcoat adhesion, and mar resistance. Andcolor-coat wiping characteristics are obtainable with the novelcomposition which are as good or better than the best qualityconventional oil-type color-coat material. Moreover, the presentinvention makes it possible to obtain new and beneficial results inapplying clear topcoats to the color coated article since superioradhesion and mar resistance can be obtained with topcoats of variouspolymersincluding acrylic polymers which give poor adhsion and marresistance when applied to a conventional oil type color coat. Theability to replace conventional cellulose nitrate and oil-type topcoatswith solutions and dispersions of clear acrylic polymers and the likeprovides important advantages in many applications. A composite finishhaving excellent resistance to becoming discolored is easily obtained.lmproved finish properties, e.g., better adhesion and mar resistance,can also be ob tained when conventional topcoats are applied to thecolor-coat of this invention.

The examples which follow are given for the purpose of illustrating theinvention. All quantities shown are on a weight basis unless otherwiseindicated.

EXAMPLE 1 A wiping-type color composition which is very useful in theapplication of a color coat, e.g., filler coat, on wood furniture andother substrates is prepared as follows.

A dispersion of fine particles of an acrylic polymer in a volatileorganic liquid is produced by (1) providing a glass-lined reactionvessel equipped with a hot water jacket, stirrer and reflux condenserand means for adding ingredients to the vessel; (2) adding to the vesseleach of the ingredients shown in formula A below (the seed stage); (3)stirring formula A at about 152 rpm for l hour while heating it at areflux temperature of 79C., using a water jacket temperature of 95C.;(4) gradually adding to the vessel over a period of 2.5 hours, by way ofthe returning reflux stream resulting from step 3, a preblended mixtureof the ingredients shown in formula B below (the feed stage), the refluxrate being such that the weight ratio of returning reflux stream toformula B entering the vessel is about 2:1, and the stirring rate beingabout 132 rpm; (5) allowing the contents of the vessel to be refluxedand stirredfor 1 hour after completion of step (4); and (6) cooling theresult ing dispersion to 22C.'

Formula Formula I Parts Parts Methyl methacrylate 1.32 17.19 Stabilizer1 I 0.52 6.11 Methyl acrylate 12.34 Hexune 14.88 Aliphatic hydrocurbon-8.32 B.R. (boiling range) l38-177C. Initiator, azobisflsobutyronitrilc)20.06 0.10

' hydroxy stearic acid, 5.22 parts of VM+P naphtha,

5.22 parts of mineral spirits, B.R. 145-2l5C., and 0.37 part of catalyst(isopropanol ester of orthotitanic acid) under an atmosphere ofnitrogen, while removing water by azeotrope distillation and keeping thetemperature below 200C, e.g., about 195C., until the theoretical volumeof water for substantially complete reaction has been removed; (b)mixing 52.00 parts of the resulting poly (l 2 hydroxy stearic acid)solution with 5.90 parts of glycidyl methacrylate, 20.97 parts VM+Pnaphtha, 20.98 parts of mineral spirits, 0.10 part of cocodimethylamine(about percent of which is the tertiary amine C, H N(CH and 05 partt-butyl catechol; (c) refluxing the resulting mixture until the acidvalue is about zero; ((1) adding gradually over a period of 3 hours tothe refluxing mixture a mixture of 1 1.74 parts of ethyl acetate and5.87 parts of butyl acetate, a mixture of 32.02 parts of the precursorsolution resulting from step (c), 16.01 parts of methyl methacrylate,0.33 parts of methacrylic acid and 0.67 part of azodiisobutyronitrile;(e) refluxing the mixture for an additional two hours; and (f) addingenough VM+P naphtha so that the resulting composition contains about 33percent of nonvolatile component. Made from a mixture containingcoconut-oil fatty acids.

The resulting acrylic polymer dispersion has an acrylic copolymercontent of about 54 percent, and a Brookfield viscosity of about 60centipoises, using a number three spindle at rpm.'The methylmethacrylate:methyl acrylate weight ratio in the copolymer is about60:40; the copolymer is amorphous; and it has a Tg of about 59C. Thefinely-divided polymer particles have an average diameter of about 0.1micron.

Next, the filler-coat composition is prepared according to formula C asfollows:

FORMULA C No. Parts 1 Aliphatic hydrocarbon, B.R. l38l77C. 5.87 2Suspending agent 1.05 3 Burnt umber pigment 7.14 4 Naphtha, VM 8L Pgrade 7.52 5 Magnesium silicate 7.07 6 Naphtha, VM & P 4.29 7 Silica,crystalline 5.86 8 Calcium sulfate, hydrous 33.23 9 Same as No. l 14.4410 Acrylic polymer dispersion, made as 13.53 described above 100.00

The suspending agent isfArmogel" from the Polyester Corporation,Southhampton, N.Y.; this is understood to be hydrogenated castor oil; itis a known-dispersion stabilizer which .renderscompositions resistant toagglomeration and settling of the dispersed particles. The formula Ccomposition ismade by (a) providing a mixing apparatus adapted to mixa'paste-like composition, for example a Cowles Dissolver; (b) addingingredients 1, 2 and 3, mixing for 10 minutes, and continuing the mixingwhile the remaining ingredients are added; (c) generally addingingredients 4 and 5 over a period of 15 minutes; (d) gradually adding apreblended mixture of ingredients 6 and 9 and a preblended mixture ofingredients 7 and 8 over a period of 1 hour, and mixing for anadditional 10 minutes; and (e) adding ingredient 10 and mixing for 25minutes.

The resulting filler composition has an acrylic polymer content of 7.31percent, a volatile aliphatic hydrocarbon content of 38.34-percent, apigment content (including pigment extender) of 53.30 percent, and apolymerzpigment ratio of about 12:88. This filler has good stabilityduring storage and shipment; it is a useful article of commerce,especially for furniture manufacturers. It can be applied to a substrateas is, or it can be diluted with a suitable volatile organic liquid tomodify its drying rate and/or to make it easier to apply by anyparticular coating methsd which might be selected.

EXAMPLE 2 A wiping-type color composition which is very useful in theapplication of a color coat (for example glaze coat) on wood furnitureand other substrates is prepared according to formula D as follows:

FORMULA D Parts No. l Van Dyke brown pigment 80 2 Acrylic polymerdispersion as 40 described above 3 Mineral spirits B.R. l452l5C. 60 4Same as No. 3 40 220 The glaze composition is made by adding ingredients1 to 3 to a ball mill and ball milling the mixture for 3 days; thenadding ingredient 4 and ball milling for minutes. The glaze has apolymer:pigment ratio of about 2 l :79; the polymer content is about 9.8percent. One gallon of the resulting glaze is mixed with 1 gallon ofkerosene just before it is to be sprayed onto a substrate.

EXAMPLE 3 Another very useful glaze is prepared by following theprocedure described in Example 2 except one gallon of the ball milledformula D is mixed with one gallon ofa preblended thinner composed of 3parts of kerosene and 1 part of di( 2-ethyl hexyl)phthalate (aplasticizer for the acrylic polymer); this is done shortly before theglaze is to be sprayed onto a substrate.

EXAMPLE 4 Articles made of wood, including tables, desks, chairs andwall panels made of oak, walnut, and mahogony, are given a verymar-resistant finish by a process which comprises the use of the Example1 filler and the Exam ple 3 glaze. The wood has relatively large pores.

First one piece of each item is stained and one piece of each item isleft free of stain. The stain, which can be any suitablenon-grain-raising stain known to be useful on wood articles, is appliedby means of a paint sprayer to the bare smoothly-sanded surfaces. Enoughof the stain is applied to give the articles the desired color; then thestain coat is dried.

Next, a clear acrylic wash coat is applied to all the stained andnon-stained articles. The wash coat is applied by means of a sprayer toa dry-film thickness of 0.2 mil. The wash coat composition is a 5percent solution of an acrylic polymer in a solvent composed of 97percent toluene, 5 percent of 2-ethoxy ethyl acetate and 3 percent of2-butoxy ethanol; the acrylic polymer is a terpolymer of 55 parts methylmethacrylate, 40 parts methyl acrylate and 5 parts dimethyl aminoethylmethacrylate. When the wash coat is dry the articles are lightly sandedto enhance surface smoothness. The wash coat lines the pores of thesubstrate without filling them, and facilitates obtaining the desiredeffect when wiping the filler coat.

A filler coat is then applied to each article by means of a paintsprayer in an amount sufficient to cover the surface thoroughly. Thefiller composition is prepared by mixing two gallons of the formula Cfiller of Example l with 2 gallons of mineral spirits. The surface iswiped with a clean piece of burlap or other suitable wiping means sothat (a) the excess filler is removed,

(b) the surface has the desired appearance, and (c) the filler remainingon the surface (residual filler) is present in the desired amount andlocation, for example in the pores and other recesses. The filler hasexcellent wiping characteristics; in fact, it is wiped more easily andeffectively than typical commercial fillers based on drying oils oroil-modified alkyd resins mixed with the solvents and pigments. Thefiller coat is dried for 15 minutes at 60C.; this removes substantiallyall the volatile ingredients but does not coalesce the polymerparticles.

The filler provides filling of the pores, leveling of the surface,emphasis of the grain pattern, and color contrast between the pores andthe rest of the substrate.

A clear acrylic sealer coat is now sprayed onto each article to adry-film thickness of 1 mil (0.001 inch). The sealer composition isprepared by mixing 1 10 parts of the 54 percent acrylic polymerdispersion described in Example 1 with a preblended mixture of (a) 46parts of mineral spirits, (b) 15 parts of 2-butoxy ethanol and (c) 30parts of 2-ethoxy ethyl acetate. Ingredients b and c serve as coalescingsolvents; thus when the sealer coat is dried, ingredients b and c causethe polymer particles to coalesce in the color coat and in the sealercoat. An integral coating structure is thereby formed.

After drying the sealer coat at 25C. for 1 hour and thereby coalescingthe color coat and sealer coat, and then lightly sanding the sealercoat, each article is spray-coated with a glaze coat in an amountsufficient to cover the surface. The glaze composition is prepared asdescribed in Example 3. The coated surface is wiped as described abovefor the filler except the burlap is replaced with a piece of cleancotton diaper material. The glaze has good wiping characteristics; it iseasy to obtain a uniform color effect where desired during wiping, andto obtain a gradual transition from dark areas to light areas. The glazecoat is dried for 10 minutes at 60C. to remove the volatile ingredientsand to cause coalescence of the polymer component; this greatly improvesits resistance to harmful changes in appearance due to handling andcontact with other articles prior to application of the topcoat. Thecoalescence is facilitated by the plasticizer present in thecomposition.

The glaze, when wiped in the desired manner, provides the finish withthe desired color and color pattern, and provides further emphasis ofthe grain pattern and figure of the wood.

Finally, each article is spray-coated with a clear acrylic topcoat to adry-film thickness of 2 mils. The topcoat composition has the sameformula as the sealer composition that was applied over the filler coat.The topcoat is dried for one-half hour at 25C. to evaporate most of thevolatile matter. To be sure that tne topcoat is fully coalesced, thesurface is sprayed lightly with 2- ethoxy ethyl acetate and dried forone-half hour at 50C. and then for 1 hour at 60C. The dried coalescedtopcoat appears to be completely transparent.

The resulting finished articles have a very attractive, decorative andprotective finish. The finish has excellent ability to retain its goodappearance when the articles are in use over an extended period of time;the finish has little or no tendency to become yellowed or otherwisediscolored. The finish is surprisingly adherent and durable; this can beconfirmed by the coin mar test mentioned above, and by attempting to marthe finish with the apparatus known in the art as the Organic CoatingAdhesion Tester, made by the U.S. Testing Company.

When Example 4 is repeated except the filler and glaze are replaced witha typical conventional filler and glaze prepared by adding pigment anddrier to a solution of a drying oil such as linseed oil, and the wipedcolor coats are given ample time to dry thoroughly, the finish has pooradhesion and durability. Instead of having excellent mar resistance likein Example 4, the finish has poor mar resistance.

A good useful finish is obtained when Example 4 is repeated except aknown flatting agent is added to the topcoat composition in an amountwhich results in a noticeable reduction in the gloss and clarity of thetop coat.

EXAMPLE Articles made of wood having relatively small pores, e.g.,maple, are given a very mar-resistant finish by (l) spraycoating eacharticle with a wiping stain made by mixing one gallon of the nondilutedglaze of Example 2 (polymer content about 9.8 percent) with 2 gallons ofmineral spirits; (2) wiping the stain coat with a clean cotton diaper toobtain the desired effect on color and grain pattern; (3) drying thestain coat for 30 minutes at 60C.; (4) applying an acrylic sealer coatas described in Example 4; (5) drying the sealer coat at 25C. for 1hour, thereby coalescing both the sealer coat and the residual staincoat; (6) lightly sanding the sealer coat; (7) applying a glaze coat anddrying and coalescing it as described in Example 4; and (5) applyingaclear acrylic top coat and drying and coalescing it as described inExample 4.

The coat of wiping stain, when wiped in the proper manner, provides thefinish with the desired color type and pattern plus an attractive accentof the pores and grain pattern.

I claim:

1. A process which comprises 1. applying to the surface of a substrate adispersion comprising a continuous organic liquid phase and a dispersedphase comprising i A. particles of a linear polymer which polymer has aTg between about 10C. and 70C., is amorphous and has at least'50 percentby weight of acrylic monomer units, said polymer being soluble in atleast one common solvent at 25C., said dispersed polymer phase beingsubstantially in- 14 soluble in said liquid at temperatures up to about38C., and B. particles of a pigment, the weight ratio of AB being about1:99 to 40:60

said dispersed polymer being present in an amount of less than 15percent by weight of the dispersion, said dispersion forming anoncoalesced layer when applied and dried by evaporation of volatilecomponents in the liquid phase at temperatures up to about 38C. andforming therefrom a layer of the dispersed phase having substantially nocoalescence,

2. wiping the layer on said surface with wiping means to attain thedesired appearance of the wiped layer on the surface and 3. coalescingthe layer to form a substantially coalesced layer.

2. A process according to claim 1 wherein the coalescing step comprisescontacting said layer with a solvent and subsequently evaporating saidsolvent.

3. A process according to claim 1 wherein the polymer in the dispersedphase has a Tg between about 40C. and C. and is at least one memberselected from the group consisting of .poly(alkyl acrylates), poly(alkylmethacrylates), interpolymers of an alkyl acrylate and an alkylmethacrylate, and interpolymers of about 50-99.9 percent by weight ofunits of an alkyl acrylate or an alkyl methacrylate and about 01-50percent by weight of units of another ethylenically unsaturated compoundselected from the group consisting of vinyl acetate, styrene, vinylchloride, vinylidene chloride.

4. A process according to claim 3 wherein the coalescing step comprisescontacting said layer with a solvent and subsequently evaporating saidsolvent.

5. A process according to claim 3 wherein the weight ratio of A:B isbetween about 5:95 and 35:65.

6. A process according to claim 5 wherein the coalescing step comprisescontacting said layer with a solvent and subsequently evaporating saidsolvent.

7. A process according to claim 3 wherein the polymer particles have anaverage diameter of about 0.05-1 micron. i

8. A process accordingto claim 7 wherein the coalescing step comprisescontacting said layer with a solvent and subsequently evaporating saidsolvent.

2. A process according to claim 1 wherein the coalescing step comprisescontacting said layer with a solvent and subsequently evaporating saidsolvent.
 2. wiping the layer on said surface with wiping means to attainthe desired appearance of the wiped layer on the surface and 3.coalescing the layer to form a substantially coalesced layer.
 3. Aprocess according to claim 1 wherein the polymer in the dispersed phasehas a Tg between about 40*C. and 70*C. and is at least one memberselected from the group consisting of poly(alkyl acrylates), poly(alkylmethacrylates), interpolymers of an alkyl acrylate and an alkylmethacrylate, and interpolymers of about 50-99.9 percent by weight ofunits of an alkyl acrylate or an alkyl methacrylate and about 0.1-50percent by weight of units of another ethylenically unsaturated compoundselected from the group consisting of vinyl acetate, styrene, vinylchloride, vinylidene chloride.
 4. A process according to claim 3 whereinthe coalescing step comprises contacting said layer with a solvent andsubsequently evaporating said solvent.
 5. A process according to claim 3wherein the weight ratio of A: B is between about 5:95 and 35:65.
 6. Aprocess according to claim 5 wherein the coalescing step comprisescontacting said layer with a solvent and subsequently evaporating saidsolvent.
 7. A process according to claim 3 wherein the polymer particleshave an average diameter of about 0.05-1 micron.
 8. A process accordingto claim 7 wherein the coalescing step comprises contacting said layerwith a solvent and subsequently evaporating said solvent.